Definition of sump
1
:a pit or reservoir serving as a drain or receptacle for liquids: such as
a
:cesspool
b
:a pit at the lowest point in a circulating or drainage system (such as the oil-circulating system of an internal combustion engine)
3
[German Sumpf, literally, marsh, from Middle High German — more at swamp]
a
:the lowest part of a mine shaft into which water drains
b
:an excavation ahead of regular work in driving a mine tunnel or sinking a mine shaft
4
:something resembling a sump :sink 2
